When Delilah first visits the lab with Jimmy she's wearing a bustier beneath her dress; in subsequent scenes she isn't. Later during the fight in the lab she takes of her dress (not shown or explained on screen) and she is then wearing her petticoat and her bustier again.
Del Blaine's dress during Banning's party and the climatic scene in the lab changes back and forth between one with multiple ties in the back and a stunt dress (with one large tie in the back) when there is more action.
When Jimmy is being tested, he drives through the alley and through the raised gate. He then drives through the area where there are tons of chicken feathers all over the place. After driving through is covered in feathers, and the grill is choked with feathers. However, when he pulls out of the alley and into the street behind the truck, the feathers are gone.
When Jimmy is fighting with the cyclist, Mitch comes over suddenly holding a tire iron and a hot dog. The cyclist forces the tire iron and to hot dog out of Mitch's hand. When the cyclist sees the officer, he walks away, and Mitch throws the hot dog at him. But at no time did we see Mitch pick up the hot dog after dropping it.
In the fight scene on top of the tower at the docks, there is one brief shot in which Del Blaine is standing at the railing with her back to the camera while Jimmy fights behind her with a rope round his neck. During this shot, it can clearly be seen that the background is actually a plain black studio curtain rather than the night sky.